Preferred Speaker Cable?

I'm sure this is the same for most audio systems, but what is the preferred cable (and cross sectional area) for speaker cable (for MRA)?

 

If the run is non-trivial (my theatre room for example is 15 metres long, and the amps are in the equipment room off the front of that), and you're running reasonably high power (everything is full THX rated and good for 400W RMS per channel), I have to tell you the difference between the 0.5 mm^2 mini-speaker-flex and the big stuff is *VERY* noticable.

I chose to run line level out to the subs, which have 400W RMS amplifiers built into their enclosure (Boston Acoustics). The other speakers, particularly front and rear main speakers when playing stuff reasonably loud, are quite obviously different.

By way of example, when I first put them in, I was short one length of the heavy-duty cable, so just ran it in standard 8-amp figure-8 flex. I could get the system balanced and flat at low volumes, but no way could I get it at moderate levels and horribly out when it was driving hard. In my previous home, I had the same equipment working fine, but it was *all* with the thinner cable, and I put the odd balance problems down to the irregular room shape.

In retrospect, the cable WAS making a difference, and as soon as I replaced the one odd length here with the same cable as the others had, it all sprang into life. Balance was achieved, response is now nice and flat (confirmed with my old HP3580A audio spectrum analyser), sound is bright, full and exciting.

I too used to think that the heavy, OFC cables were more **** value than anything else, have to concede that at least *heavy* cables are better, and the longer the run the more improvement they make. OFC I'm still to be convinced of.

 

Except if your jumper leads look like this!

 

One important and often forgotten factor is that the Damping Factor gets completely screwed up unless there is a really low resistance between Amp and Speakers.

The damping factor is what "slows the cone" - stops it overshooting when playing bass notes. Basically, when the speaker cone is moving forward you need to stop it and move it backwards accurately, and that can only be done if the amp can get the electricity there "easily". That's a really bad explanation, hope it makes sense.

If the damping factor's not right, the bass is muddled and also there's harmonics created at higher frequencies. This explains the clearly audible difference in bass and overall clarity when crap cables are swapped for low resistance ones in a high-end system with decent grunt.

As others said, it doesn't make much difference at low power (<50W) and short runs, and/or if there's no bass in the speakers anyway. As far as I know the MRA amps are only like 10 or 20W per channel - at that low power normal figure 8 (of reasonable size) is gunna work OK unless it's a long run.

When I first moved into my house they'd wired a stereo pair from the lounge via the garage to a cabana down in the backyard. The run was at least 50 metres and they used standard lamp cord (0.75mm?) as speaker flex.

The sound that came out was almost "ambient" - there was absolutely NO bass at all, and a kind of haunting, spiritual sound effect to the music. I disconnected it within about 10 minutes, as it sounded too poxy with AC/DC and similar playing thru it!

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But hey - speaker cable is cheap - you can buy a roll of nice thick "jumbo" cable from Jaycar and similar retailers really cheaply - and you'd have to be a super-audiophile to detect any difference between OFC and standard cables *OF THE SAME CROSS SECTIONAL AREA*... most comparo tests re: OFC that I've read are very amusing.

JC

 

Thanks all - will do some testing once the MRA is released here in SA and will post if anything eerie, "ambient" or weird happens.

 

I've read the posts above and would add the following.

The minimum cable should be is 16 gauge speaker cable....Not figure 8 security.

Check out http://www.audioholics.com/techtips/audioprinciples/interconnects/SpeakerCableFaceoff.htm

It looks at a bundle (no pun intended) of cables and compares them price wise, and most importantly inductance/ft at a given frequency. If you are paying less than about $1.00/metre, then the cable would be best suited to a cheap stereo system.

If you/your client is buying equipment of the level of the C-Bus music system (and I would imagine a good level of speaker too), then cable shouldn't be the weak link.

No need to go overboard, but no need to use cheap crappy cable either.

BTW... The best we have used is the Liberty 4 core cable for multi-zone applications. You can run out left and right speaker in a single jacket cable... especially good when you get back to the amp (assuming you use a muilti-zone amp)? only half the number of cables coming down the wall.

Cheers

 

Might be a bit late but

Out of the Belden catalogue, here is a chart that helps size speaker cable


4 Ohm speaker___________8 Ohm speaker
Loss % 11%__21%__50%____11%__21%___50%
LossdB 0.5__1____3______0.5__1_____3
Gauge Meters
12____42.7__93.0_350.6__86.5_186.0_696.6
14____27.4__59.5_225.6__56.4_120.4_451.2
16____18.3__38.1_143.3__35.1__76.2_285.1
18____12.2__27.4_103.7__25.9__57.9_208.8
20_____7.6__15.2__59.5__15.2__32.0_118.9
22_____4.6__10.7__41.2__10.7__21.3__83.8
24_____3.0___7.6__25.9___6.1__13.7__51.8


For theaters I use the .5 dB as a maximum, distributed audio 1 dB.

Sorry about the underscores, trying to get the columns to line up.

 

The # (code) tag is a good way to do what you need... it uses a fixed-width font and allows you to retain spaces or tabs as indenting. Easiest to prepare in Notepad, then paste it back thus :

Code:

          4 Ohm speaker        8 Ohm speaker 
Loss %   11%   21%   50%      11%    21%   50%
LossdB   0.5   1      3       0.5    1      3
Gauge   Meters 
12      42.7  93.0  350.6    86.5  186.0  696.6 
14      27.4  59.5  225.6    56.4  120.4  451.2 
16      18.3  38.1  143.3    35.1   76.2  285.1 
18      12.2  27.4  103.7    25.9   57.9  208.8 
20       7.6  15.2   59.5    15.2   32.0  118.9 
22       4.6  10.7   41.2    10.7   21.3   83.8 
24       3.0   7.6   25.9     6.1   13.7   51.8

I just added a few spaces to make it easier to read

Cheers, John